For three dimensional gesture recognition, e.g. the recognition of wipe and approximation gestures, sensors are required that are capable to detect the position, the movement and the orientation of hands.
Besides the use of cameras, the use of simple LED and photo diode-based concepts is of special interest due to the related cost.
A significant problem known from the state of the art is the available assembly space. Different methods have been developed to improve the robustness against external light and other disturbances.
State of the art systems are known to have a generator (G) producing a transmitter signal (S5), through which a transmitter (H) is fed. The transmitter (H) transmits into a receiver (D) having passed the transmission path to be measured, which consists of a first partial transmission path (I1) and a second partial transmission path (I2). The receiver output signal (S0) of the receiver (D) is converted to a compensation signal (S3) by a controller (CT), through which a compensation transmitter (K) is fed, which transmits typically in a linear superimposing manner into the third transmission path (I3) as well as into the receiver (D).
Thereby the compensation signal (S3) is generated in such a way by the controller (CT) out of the receiver output signal (S0) and the transmitter signal (S5), that the receiver output signal (S0) contains no remaining components of the transmitter signal (S5), with the exception of system noise and a control error. These types of systems, called HALIOS systems in the following sections, are especially robust towards sources of interference, such as sun light, while simultaneously being robust towards dirt and the drift of a receiver (D). One such HALIOS system is for example known from the DE102010014462A1 or the EP2418512A1.
Overall there are two basic versions known of the HALIOS system from the state of the art, which can for example also be combined by switching between them or by smooth transitions between the different controller properties. Because the first claim refers to Halios systems in general, in following the definition for such state of the art Halios systems is given, to be able to keep the claims short and compact.
A Halios system in the sense of this disclosure is characterized hereby, that
i. either in the first version
                a. it possesses at minimum one signal generator (G) able to generate at minimum one transmitter signal (S5), driving at minimum one transmitter (H), that irradiates into at minimum one receiver (D) and        b. it possesses at minimum one controller (CT), which puts out at minimum one compensation signal (S3), by which at minimum one compensation transmitter (K) is driven, which also transmits in a superimposing manner into the at minimum one of the said receivers (D) and        c. that the said controller (CT) generates the minimum of one said compensation signal (S3), of at minimum one of the receiver output signals (S0) of said receiver (D), and of at minimum one of the said transmitter signal (S5), and        d. and that the controller (CT) drives the minimum of one compensation transmitter (K) by way of said compensation signal (S3), that said receiver output signal (S0) of said receiver (D) contains no remaining components of the transmitter signal (S5) except for a control error and system noise.or in the second version        e. it possesses a minimum of one signal generator (G), capable of producing the minimum of compensation signal (S3), by which the minimum of one compensation transmitter (K) is controlled, which at minimum transmits into one receiver (D) and        f. it possesses the minimum of one controller (CT) emitting the minimum of one transmitter signal (S5) which drives the minimum one transmitter (H), which also transmits in a superimposing manner into the at minimum one receiver (D), and        g. that said controller (CT) generates the at minimum one of said transmitter signal (S5) out of a minimum of a receiver output signal (S0) of one of the said receivers (D) and at minimum one compensation transmitter signal (S3), and        h. and that the controller (CT) drives a minimum one transmitter (H) by way of a minimum of one said transmitter signal (S5) in such a way that the receiver output signal (S0) of said receiver (D) contains no remaining components of the compensation transmitter signal (S3) except for a control error and system noiseor        i. that it is a combination of the first and second versionand            ii. that at minimum of said optical transmitters (H) it is able to transmit at minimum into a first transmission path (I1) which is only a partial component of the device, and    iii. which terminates at minimum one object (O), which is not part of the device, located at the end of the first transmission path (I1), and able to transmit light into at minimum of a second transmission path (I2), which is only a partial component of the device, and which terminates at minimum one of the said receivers (D), which is part of the device, and    iv. that at minimum one of these receivers (D), which is able to receive the transmitter signal (S5) modified by the transmission through the first transmission path (I1) and/or the second transmission path (I2) and/or the reflection by the object (O) and to transform the transmitter signal (S5) at minimum into one receiver output signal (S0) and    v. that one of said controllers (CT), which is part of the device, outputs the minimum of one signal (S4), which may be used outside the device and    vi. that this signal (S4) represents the measure of a minimum of one feature, at minimum of one first transmission path (I1) or one second transmission path, or representative reading at minimum for one property at minimum for one object (O) at the end of one of the said first transmission paths (I1) or at the beginning of said second transmission path (I2), and over an output signal (S4) at minimum, emitted upon request and    vii. that this compensation transmitter (K) transmits into at minimum one third transmission path (I3), which is entirely a component of the device and    viii. that at minimum one of the third transmission paths (I3) terminates at the minimum by one said receiver (D) and    ix. that at minimum this receiver (D) is capable of picking up at minimum the signal in said compensation transmitter (K), superimposed with the signal at minimum by one transmitter (H)
If such a Halios system is to be installed into a single SMD housing, there are several challenges to be met, in reference to optics and workability.
This problem is not resolved by DE102010014462A1, as this document does not reveal the optics. A series of optical components and potential arranging of optical elements may be taken from the document DE102010028967A1, in reference to such Halios systems. In conjunction with the elaboration of the disclosure at hand, it was noticed that the backscattering of the light of the compensation transmitter (K) to the receiver (D), typically by a photodiode, and from there to the object (O), and from there again back into the receiver (D) results in a disturbance signal in the receiver (D). The problem made itself noticed as an environment-dependent basic coupling. This problem is not mentioned nor resolved in DE102010028967A1. The semitransparent mirror (e.g. FIG. 9, reference sign 192 of DE102010028967A1) listed there still results in a continued radition of light from the compensation transmitters, which then might be scattered towards the object. Also, typically an overloading of the receiver (D) occurs caused by the compensation transmitter (K). It was also noticed, that the known state of the art devices, despite all diligence, show a temperature dependency of the test reading, which could be explained and corrected within the framework of the invention, and could be ascribed to the problem of the differing dampening from the transmission path and compensation path.
A model of the state of the art housing, which addresses the problem of an environment-dependent basic coupling, is known from the published patent application DE102012210891A1.
Generally there are the transmitter (H) the object (O), each within the transmission paths and the receiver (D): The actual transmission path (I1 & I2, I3) and a parasitic transmission path.
The light of the transmitter (H) may be transmitted from the transmitter (H) to the object (O) first and from there it may be reflected to the photodiode, the receiver (D). In this way the light of the transmitter (H) should initially be sent from transmitter (H) to object (O), and from there reflected back to the photo diode, the receiver (D). The light of the transmitter (H) should not directly fall on to the photo diode (D). In reference to the light of the compensation transmitter (K) it is the opposite: It should fall directly on the photodiode (D), and if possible not be dispersed onto the object (O). Hereby a maximum of the transmitted energy should reach the object to be detected, and a maximum of the reflecting light of the object is to be captured by a receiver. For this, for example in the state of the art DE102012210891A1, a lens is proposed which is arranged coaxially to the center point of the transmitter or receiver. (FIG. 3 of DE102012210891A1). A problem of the technology disclosed by DE102012210891A1 is that the illumination of the space is significantly lower than that of the device which is part of the invention. The lenses (reference numbers 218 and 312 of DE102012210891A1) are lowered around a low rim relative to the top cover (reference numbers 219 and 319 of DE102012210891A1). It further limits the illumination. The necessary spatial illumination is achieved through a complex three-dimensional arrangement of several sensor modules in accordance with DE102012210891A1 (FIG. 6 of DE102012210891A1). The patent application DE102010027499A1 resolves this illumination problem similarly (FIG. 1 of DE102010027499A1) by use of multiple modules corresponding to DE102010027499A1.
The described illumination problem is similarly resolved in the European patent application EP2549652A2. However the three-dimensional assembly is not carried out on module level but on component level. This complex three-dimensional assembly of transmitters and receivers already achieves an improved spatial illumination in comparison to DE102012210891A1 (FIGS. 5a and 5b of EP2549652A2). Thereby the lenses are always arranged coaxially to the transmitters and receivers (FIGS. 2 and 4 of EP2549652A2) as disclosed in DE102012210891A1. Here as well a u-shaped housing (reference number 130 of EP2549652A2) causes shadowing on the receiver (reference number 200 of EP2549652A2) whose receiver beams are limited through the trough walls.
In the text WO20131134456A1 an assembly is disclosed in which a HALIOS system is taking advantage of glass fibers within a PCB. The transmission diode (reference number 102 of WO20131134456A1) is marked in FIG. 1 of said patent application in conjunction with a lens, which is in turn arranged centrically. Said shadowing problem is caused by the walls of the mounting hole. (reference number 109 of WO20131134456A1). Therefore the illumination is also not optimal here.
This problem is solved significantly better in patent application DE102006020570A1. It is not, however, the objective of the system to supervise the entire open space above the system, but only a limited space immediately above the sensor system. As previously, the central lens (reference numbers 21 and 53 of DE102006020570A1) is arranged centrically relative to the receiver (reference number E of DE102006020570A1). A symmetrical illumination is not possible in this solution. The transmitters do not feature lenses.
A significant problem in the integration of such HALIOS systems in one housing is the suppression of parasitic couplings. The miniaturization accentuates the problem, identified as cross-talk in the following paragraphs. Especially the exposure of the measuring object to scattered light from the compensation transmitter (K) changes hereby the basic coupling dependent on the usage situation which was already described in the European patent application EP2418512A1.
And finally, in the state of the art the problem of temperature dependency is neither recognized nor does it give solutions for it. There will be responses to this problem and additional writings from the state of the art in the following description of the invention for the distinction of this disclosure towards the state of the art. It is stated in advance, that none of the state of the art publications, mentioned previously and in following, address the problem of the situation-dependent basic coupling of scattered light from the compensation transmitter.